1. Field
The present disclosure generally relates to multi-mode power amplifiers having improved linearity.
2. Description of the Related Art
In wireless communication applications, size, cost, and performance are examples of factors that can be important for a given product. For example, to reduce both of the cost and product size, wireless components such as multi-mode and multi band power amplifiers are becoming more popular. In an example context of power amplifier (PA) products, some PA devices can be configured to provide dual mode functionalities such as GPRS (general packet radio service) and EDGE (enhanced data rates for GSM evolution) modes.
In many radio-frequency (RF) applications, a PA typically includes an amplifying transistor such as a heterojunction bipolar transistor (HBT). An input RF signal can be provided to the base of such a transistor, and the amplified RF signal can be output through the collector of the transistor. Supply voltage for the transistor can be provided to the collector, and a bias signal can be provided to the base. Such a bias signal is typically provided by a bias circuit.